* {
  box-sizing: border-box;
}

.grail-layout-x {
  padding: 0 100px;
  width: 400px;
  height: 400px;
}

.left {
  float: left;
  margin-left: -100px;
  width: 100px;
  height: 100%;
  background-color: #f66;
}

.right {
  float: right;
  margin-right: -100px;
  width: 100px;
  height: 100%;
  background-color: #66f;
}

.center {
  height: 100%;
  background-color: #3c9;
}